Field Sequential LCD Correction Voltage for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Field sequential type liquid crystal display devices experience flickers and luminance unevenness due to voltage fluctuations caused by leakage currents in pixel TFTs, especially when using high-response liquid crystal materials, which affect image quality and light utilization efficiency.
Innovation Solution
A control method that divides the frame period into writing and display periods, applying a correction voltage different from the video signal during the display period to equalize leakage current fluctuations and improve pixel voltage stability, thereby reducing flickers and enhancing light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If field sequential type liquid crystal display device uses high-response liquid crystal material, then response speed is improved, but flickers and luminance unevenness occur due to voltage fluctuations from leakage currents
Solution Approach 1:
The patent applies a correction voltage during the display period before the leakage current causes significant voltage fluctuation. By proactively compensating for the expected voltage drop due to leakage current, the system prevents flickers and luminance unevenness before they occur, maintaining both high response speed and image quality.
Solution Approach 2:
The patent implements a feedback mechanism where the correction voltage is determined based on the relationship between the video signal voltage and the leakage current characteristics. The control circuit continuously monitors and adjusts the correction voltage to compensate for voltage fluctuations, ensuring stable display performance despite high-speed liquid crystal response.
2Stability of the object's composition
If correction voltage is applied during display period, then voltage stability is improved and flickers are reduced, but device complexity increases
Solution Approach 1:
The patent changes the voltage parameter by applying a correction voltage during the display period. The correction voltage is calculated based on the video signal voltage and leakage current characteristics, adjusting the electrical parameters to maintain pixel voltage stability without requiring complex hardware modifications.
Solution Approach 2:
The control circuit performs multiple functions: it generates the video signal, determines the correction voltage based on leakage current characteristics, and applies the corrected voltage during the display period. By integrating these functions into a single control mechanism, the patent reduces overall device complexity while achieving voltage stability.
3Use of energy by moving object
If pixel area is increased to improve light utilization, then light utilization efficiency is improved, but resolution decreases when pixel is divided into sub-pixels
Solution Approach 1:
The patent employs field sequential color display with periodic action, where the entire pixel area is used for each color field (red, green, blue) in sequence. By displaying different colors in different time periods rather than spatially dividing pixels into sub-pixels, the system maintains large pixel area for high light utilization efficiency while achieving full-color display and high resolution.
Data Source
AI summary
The present invention aims to reduce flickers of the liquid crystal display device and enable the use of liquid crystal material exhibiting a high response speed, and to enhance light usage efficiency of the field sequential type liquid crystal display device. After writing the video signal to all the pixels in each sub-frame period, a correction voltage signal or an alternating signal having a frequency of greater than or equal to a certain frequency is input to the data line, so that the magnitude of the leakage current of each pixel TFT caused by the difference in polarity of the video signal with respect to the opposing electrode written to the pixel electrode is equalized, and the flickers are greatly reduced.